Two official investigations into the outbreak concluded that the most likely sources of the foot-and-mouth virus were two nearby laboratories at Pirbright which stocked samples of the same form of virus that had infected local animals.

Merial strongly denies it is responsible for last summer's outbreak and will vigorously defend any claims

Philip Connolly, spokesman for Merial Animal Health Limited

These were the Institute for Animal Health, which is a publicly-funded research organisation, and Merial Animal Health Limited, a privately run vaccine production company.

The investigators concluded the virus had escaped from the broken drainage system which served both laboratories; but they were unable to pinpoint which of the two facilities as responsible for the leak.

The inquiries also criticised the Department for Environment, Food and Rural Affairs (Defra) which is responsible for running the Pirbright site.

It emerged that Defra knew the two laboratories considered the old effluent drains ought to be renewed. Defra was at the time responsible for inspecting the laboratories.

The 14 farmers are alleging that the Laboratories and Defra are jointly and severally responsible for the losses they incurred as a result of the outbreak which total about £1.5m.

'New start'

The laboratories are alleged to have breached their duty of care in handling the foot-and-mouth virus and Defra is alleged to have been negligent in its running of the site.

The firm's Peter Cusick told BBC News: "The case against the government relates to their role as a regulator of the site. They had a duty to perform that role properly and failed to do that in a number of respects.

"They knew, for example, live virus was getting into the effluent system. They also knew about the state of the drains and how both laboratories wanted those drains renewed."

One of the farmers suing the government is John Emerson of Hunts Hill Farm in Normandy.

All his 362 calves, pigs, cattle, and sheep had to be slaughtered as some of his animals were thought to have been in contact with infected animals. It turned out that none of them had been infected - but they were killed by government vets as a precaution.

He had to buy and rear new stock. "It's a fresh start," he explained. "We started this business 14 years ago and it's basically turned the clock right back and starting from fresh again."

Union support

Mr Emerson said that the compensation he received for the animals did not make up for his losses which he estimated to be in excess of £100,000.

"It's been quite devastating," he said. "It's been quite hard - it's a lot harder work than it has been previously. We're having to work longer hours."

The case is being backed by the National Farmers' Union which is angry that thousands of its members did not receive any compensation at all for the export ban and movement restrictions that were introduced to control the spread of the infection.

The NFU's President Peter Kendall estimates that these losses are in excess of £100m.

"There are other countries around the world who look at their agriculture in a much more supportive way. And particularly if the government have been involved in the damage that's been incurred, you'd expect a much more sympathetic and helpful response," he told BBC News.

Consistent position

According to Mr Kendall, if the test case is successful the government will have to consider compensating all those affected, or risk further legal action. But he said that money was not the only motivation for bringing the case.

"What's absolutely critical is that we make sure that anyone that can be responsible for damaging the industry, to the degree that foot-and-mouth damaged farming last year, must know that someone must challenge them if it happens again.

"I want compensation for those impacted farmers; but I also want the Institute for Animal Health, also Merial, and the Secretary of State (for Defra) who licenses Pirbright, to know that they are responsible and the courts will hold them responsible."

Both the Institute for Animal Health and Merial have consistently denied that they failed in their duty of care in handling the foot-and-mouth virus.

Merial spokesman Philip Connolly said: "Merial strongly denies it is responsible for last summer's outbreak and will vigorously defend any claims."

The Institute for Animal Health also issued a statement in response to the farmers' legal action.

"We confirm that proceedings have been issued against the Institute for Animal Health by various persons seeking damages arising from the outbreak of FMD in 2007," the institute stated.

"The claim, which appears to us to be speculative, will be defended. We will issue further statements when we have something additional to say."

Defra has also consistently denied that it was negligent in regulating and inspecting the Pirbright site.

"The government recognises the strain on the farming industry that resulted from the foot-and-mouth disease outbreak last year and we have made every effort to help the industry return to normal," the department said in a statement.

"Statutory compensation has been paid where animals were slaughtered. However, while we cannot comment on the detail of this specific case, Defra will deny liability in this action."

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